This K23 Mentored Patient Oriented Clinical Research Development Award application outlines a program of research to study modifiable risk factors for chronic posttraumatic stress disorder in urban, inner-city adolescents exposed to community violence. The career development and research plans are designed for the candidate to obtain training in the methodology of longitudinal data collection, the identification of risk factors for chronic PTSD, and an opportunity to incorporate psychophysiological types of assessment into studies of traumatized adolescents. The candidate is an Assistant Professor of Psychiatry and Child Psychiatry at Yale University School of Medicine (YUSM) with a clinical background in pediatrics, psychiatry and advanced clinical training in child psychiatry. Dr Steven Southwick, Program Co-Director of the Clinical Neuroscience Division of the National Center for Posttraumatic Stress Disorder and a Professor of Psychiatry at YUSM will serve as the candidate's Mentor. Preceptors at YUSM include Dr Carolyn Mazure, Dr Linda Mayes and Dr Walter Anyan. Dr Robert Pynoos, Professor of Psychiatry at UCLA, who directs the UCLA trauma program will act as a child trauma consultant and Dr Paul Maciejewskis will provide biostatistical consultation to the project. In the proposed research program, the candidate will conduct a multi-modal, baseline assessment and follow up assessments at three time points over two years of 150 inner-city adolescents, recruited from a hospital-and four school-based primary care clinics who, within the proceeding three months, have experienced an episode of community violence that meets DSM-IV defined, Criterion A stressor requirements. This project will examine the moderating effect of three potential modifiable risk factors (social support, family function, and types of coping skills) for the development of chronic, persistent PTSD. In addition, the project will track other psychopathology, psychosocial functioning, intervening traumas, behavioral outcomes (substance use, teen pregnancies, school attendance, arrest rates and medical treatment utilization) in this cohort of urban, inner- city adolescents. A psychophysiological assessment of hyper arousal will examine the role of acoustic startle responses as an objective marker of hyper arousal symptoms in this population.